1. Field of the Invention
The present invention relates to a sensor and, more particularly, to a rotation sensor applied to digital imaging devices.
2. Description of Related Art
In recent years, owing to the continual progress of electronic technologies, digital photography products such as mobile phones, digital cameras and digital camcorders have become indispensable articles in everyday lives of many people. A digital camcorder or a digital camera with the video-capturing function can simultaneously record image and sound to allow people to recall the situation at that time through the cooperation of image and sound.
Among various digital imaging devices, digital cameras are the most popular. When one uses a conventional digital camera, he can only take pictures in accordance with the set horizontal or vertical angle of the viewfinder window and the LCD screen of the digital camera. Therefore, the storage of digital image frames depends on the angle of the digital camera relative to the horizontal direction of the camera body at the time when taking pictures. If the user holds the digital camera in the horizontal direction to capture images, the photographed sceneries in the stored image frames will show a normal erected state. If the user holds the digital camera in the vertical direction to capture images, the photographed sceneries in the stored image frames will show a laid-down state. Therefore, when the user views the photographed images on the LCD screen of the digital camera or edits the photographed images on a display using a computer, the photographed sceneries will show an erected or a laid-down state according to the photographing angle. This not only will cause inconvenience and discomfort in image viewing, but will also result in visual misjudgment during image editing to affect the editing efficiency and effect.
Many manufacturers have added a rotation sensor in the digital camera to solve the above problem. The most common rotation sensor is shown in FIG. 1. A receiving room 12 is disposed on a circuit board 10 of a digital camera. Conducting strips 14 are disposed on all the walls of the receiving room 12. A metal bead 16 is placed in the receiving room 12. When the body of the digital camera is rotated, the metal bead 16 will roll with the rotation of the camera body to allow the metal bead 16 to touch the conducting strips 14. Through the detection of the conducting strips 14, the digital camera can know whether the camera body is horizontal or vertical when taking an image so as to store the taken picture into a corresponding image frame for accurate display of the taken image.
In addition to the picture-taking function, today's digital cameras usually have a video-capturing function and a sound-recording function. During the video-capturing process, however, the digital cameras will also record the rolling sound of the metal bead in the rotation sensor, hence generating noise during the video-capturing process. Besides, the rolling bead type rotation sensor will easily misjudge during detection because that the rolling speed of the metal bead is generally slower tan the photographing speed. Furthermore, the rolling bead type rotation sensor is complicated and expensive in structure and manufacturing cost, hence making digital cameras having the rotation sensor very expensive.
The present invention aims to propose a rotation sensor to solve the above problems in the prior art.